balanced are they worth it?

I am thinking of upgrading to transparent ultra from supers and was told that balanced are better and worth the extra cost ? please no transparent bashers this is only a balance questions.
It has been my experience that when dealing with long lengths (say 3m or more) that balanced is the way to go. If we are talking about a 1m or 1.5m length then you will probably not "hear" any difference between the xlr or rca versions unless your gear is subject to picking up hums via cables draped over each other, etc. Of course your measurements may vary. Sometimes we audiofools tend to be happier when we know we have done everything to maximize our return and using balanced cables gives us this "piece of mind" irregardless of whether we can distinguish any differences or not...
I switched from Super balanced to Ultra and I have been very happy with the results. From what I have read on posts here though it can be very system dependent. So I would make sure the dealer is willing to swap them back if you do not feel it is worth the bucks. You may want to try single ended "reference". If I remember correctly they are around the same price. Good luck.
In my system, balanced cables perform much better. I get greater gain and a much more open sound. In comparison, RCA cables sound quiet and compressed. However, I do feel that cable performance is system dependent, so results will vary. Furthermore, I have used both Transparent Super and Ultra cables. I feel that the Ultra is a significant improvement over the Super. And, the XLR version is even better: clean, open, and smooth. If you would like more information, please email me. I would be happy to discuss this topic with you.
One thing not stated here is the equipment, meaning, are you using the XLR cables on equipment that has been designed as a balanced circuit? It is my experience (with my Amp, DAC, and Tuner) that some equipment sounds better with XLR because of its circuitry. You should consider this as well. It often is the reason why short XLR runs (.5m or 1m, not just long runs, will sound better. Good luck!
If the gear is truly balanced then you null out the second harmonic using balanced cables, but little of the gear with balanced connectors is truly balanced. Given a clean ground single ended wires will perform as well as balanced wires in the bulk of the cases.....Clean ground is the rub.....
2 things that have been mentioned are important: the length needs to be over 2 meters (probably 3) for you to hear a difference. This is true, unless the equipment you are using has a fully balanced topology within it (as Mento refers to). If that is the case, then balanced will almost always sound better. Another issue which has not been mentioned is the environment. If you live in an area with alot of RFI and EMI, balanced will make a substantial improvement by just canceling out the noise that is picked up from these sources. This occurs because the 2 hot leads are out of phase. It of course does not eliminate all of the EMI/RFI noise, but it does reduce it significantly.
What I have done in the past is contacted the manufacturers of the equipment and asked them their opinions.
I recently changed from unbalanced to balanced, 3 months ago, and I've been pleased. I would say overall, the noise floor is definitly lower. The instruments come from a blacker, darker background, if you will. The strange thing I've noticed though, is that I have a harder time telling the difference between cables. For example, the difference between XLO Reference and Signature seems much more pronounced to me unbalanced then in the balanced form. Maybe I'm crazy (my wife won't disagree) but I prefer the balanced form overall. Gotta go , Dickie Betts is jamming, man this sh@t sounds good.
Thanks evryone for your response to answer the question on equpment used it is a proceed hpa3 and a 20 ft run.